In a conventional light-emitting diode chip, an electrically conductive contact structure is applied on the radiation exit area. The contact structure is usually embodied in such a way that, on the one hand, a large amount of light can emerge from the surface of the light-emitting diode chip such that the shading by the contact structure is as small as possible. On the other hand, in semiconductors having a relatively low transverse conductivity such as, for example, nitride semiconductor compounds, the current density is intended to be distributed as homogeneously as possible over the surface of the light-emitting diode chip. Consequently, inhomogeneous electric fields which, by way of example, can arise in the vicinity of a bonding pad and lead to inhomogeneous current density distributions can be avoided.
In the case of luminescence diodes having an edge length of less than approximately 300 μm, with a bonding pad arranged centrally on the radiation coupling-out area, it is possible to achieve a comparatively homogeneous current distribution in the diode chip. However, the bonding wire projecting beyond the surface brings about a shading of the radiation exit area or a reduction of the proportion of radiation coupled out. In the case of large-area luminescence diode chips having an edge length of up to 1 mm, for example, this type of contact-connection can lead to an inhomogeneous energization.
To increase the proportion of radiation coupled out, DE 102005025416 A1 describes, in the case of a luminescence diode chip, arranging the bonding pad in an edge region of the radiation exit area.
It could thus be helpful to provide an electroluminescent device and a method for producing an electroluminescent device wherein the emission of radiation is increased further.